A rocking contactor switch mechanism comprises a contactor pivotally supported at the end of a stationary contact blade to rock or teeter into and out of engagement with stationary contacts mounted on either side of the supporting contact. A spring biased plunger is driven linearly along the surface of the contactor to actuate it from one position to the other as the plunger moves across the pivot point which is the perpendicular plane of the supporting contact blade. The pivot point for the contactor is also the current carrying connection between the contactor and blade contact whereby the contactor electrically bridges an outer stationary contact with the supporting blade contact. For smooth operation and good current transfer between the contactor and the supporting blade contact, it is important that the pivot edge of the blade contact be smooth along its length for uniform engagement with the contactor. To further enhance current transfer between these members it is customary to plate one or both members with a superior current conducting metal such as the precious metals gold or silver.
An economically preferred method of manufacturing contact terminals for use in switches of this type is to blank the members from a metal sheet. This process creates a clean cut approximately halfway through the metal and then shears or tears the material through the balance of the thickness. The resulting edge is smooth only for a portion and has a relatively rough surface on the other portion and is therefore undesirable as a pivot edge for a contactor. Another problem exists with respect to plating the supporting blade contact terminal. The member can most readily be bulk plated, although in such process the entire piece contains plating of silver or gold, which is economically undesirable. An alternative method is to plate a selective area of the stationary contact blade, but this is a more complicated process.
Another problem associated with contact mechanisms of this type is the assembly of the spring biased plunger to the switch operator. In most designs a blind hole is provided in a linearly moveable operator and a hollow plunger element with a spherical end is provided in the open end of this hole. A helical compression spring is disposed within the holes of the plunger and the operator to bias the plunger outwardly against the contactor surface. It is necessary to subassemble the switching mechanism and the operator before positioning the parts within a housing, and in the aforementioned devices the spring loaded plunger provides an unstable condition for the subassembly prior to final assembly.